Well, In the icy snow I got under the hood and car and found nothing out of place. Its cold as hell, the car might just be making more power without boost. I got out on the I-40 to 275 cut-off and was making plenty of power. Boost gauge was showing solid 24-25lbs then slightly bringing it back to 21-22 before shifting up(auto).

I wasn't going to put the cold-side pipe on, but while playing around with removing the stock pipe I broke the plastic nipple while removing the vacumn line.(I pulled the line free with the nipple still attached, just using my hand. It was cracked into the main body, not just the nipple breaking off)

I think the main difference in sound is because I upgraded both pipes. I had a really great sound with just the Hot-side pipes, I wonder if this has anything to do with an imbalance of tube diameter. If anyone has a cold-side stock pipe laying around I might be intrested in buying, or I should be able to tap a nipple in the old one.

Panel-thanks for clearing up which pipe was which.

 

From a technical perspective, I would think that the Hahn piping would exhibit less friction loss, freeing up the turbine's input head pressure. Simply put, the turbo might not have to "pull" as much pressure as with the restrictive stock cold air piping. This may, in theory, silence the turbo whine to some extent.

I recently done some calcs on this very subject for a different application. I decided to spare the geek equation for this posting, but if anyone want's to see the calcs (if they want to fabricate a custom intake), I'll be glad to post them. let me know.

 

87 Silver, I was leaning this way, but wow the sound drop-off is huge between the stock pipe and aftermarket. It sounded great with the hot-side pipe, but once the cold-side was on, the sound was gone! I am/was beginning to think the BCV is bad.

 

You probably won't hear the sound of your turbo spooling up, but if you space up the lid on your air box about 3/4", you sure can hear the BOV louder, plus get more air in there. "Moon"

 

Youre getting better flow with the hot/cold pipes on the car. I did both of mine the same day so i dont remember the sound difference. And yeah do what moonsign says.

 

So did you notice any power improvement with the cold side done?

How was the install effort foe both? The hot side is the only side you really see.

 

Hey Gasman,

I noticed better throttle response. before it seemed that the boost didn't build as quickly as it does now.... the best way to describe it the boost comes on really strong really quick, with less effort.

I posted a thread on the install:https://www.chevyhhr.net/forums/2-0l-performance-tech-46/happiness-its-way-32811/

 

Hmm... better response is quicker to get the fast down the road. But damn... I'd miss the turbo whine.

 

Yeah, I was bummed about that, sounded really good...... I think a BOV is in my future as I just don't trust the plastic housing of the BCV. I may also try moonsign's Idea of jacking the cover a little bit. So I will try and get some sound back. I am really beginning to think that the great sound I was hearing was an imbalance created by two diffrent sized pipes? If I could do it again I'd leave the bottom pipe off.....putting that pie on killed the sound

 

So you would just do the hot side.... hmmmm